Further Studies on Placental ACTH, Pituitary, and Adrenal-Hyaluronidase Relations

During the past several years, an investigation has been made of the relationships between various hormones of the adrenal cortex, the enzyme hyaluronidase, and its substrate hyaluronic acid, with specific reference to tissue permeability and collagen diseases. As the studies progressed, several problems were investigated: (i) which fractions of the adrenal cortex were responsible for the results obtained, (ii) what mechanism or mechanisms of action were involved, (iii) in what way the placenta, as well as the pituitary gland, was involved in hyaluronic acid metabolism in relation to connective tissue disease processes. In other studies, experimental evidence has suggested an action of these adrenal hormones on the enzyme hyaluronidase in vitro," while desoxycorticosterone, growth hormone, and the related sex steroids, are without hyaluronidase-inhibitory effect. Adrenocorticotrophic hormone was demonstrated to be a potent inhibitor of the hyaluronidase-enhanced spreading phenomenon through the release of the effective C-il adrenal steroids in the intact rabbit, rat, guinea pig, mouse, and dog.'" In view of the favorable influence of pregnancy on certain of the collagen diseases, it was of interest to demonstrate that chorionic gonadotrophin obtained from human pregnancy urine exhibited marked hyaluronidase-inhibitory activity in normal, castrate, and hypophysectomized animals of both